Work

Identification and purification of a single-stranded-DNA-specific exonuclease encoded by the recJ gene of Escherichia coli.

Year: 1989

Type: article

Abstract: The Escherichia coli recJ gene product was overproduced using a plasmid that carries the recJ gene downstream of a strong regulatable promoter and a strong ribosome-binding site. Overexpression of recJ produced a concomitant increase in the levels of single-stranded-DNA-specific nuclease activity present in crude cell extracts. This nuclease activity was purified to homogeneity and found to reside in a 60-kDa polypeptide. This polypeptide was induced with recJ overexpression and had the size and N-terminal amino acid sequence identical to the predicted RecJ protein sequence. The RecJ nuclease degraded linear single-stranded DNA but did not have exonuclease activity on linear double-stranded substrates or endonuclease activity on either single-stranded or double-stranded substrates. The RecJ exonuclease had greater activity on duplex DNA molecules with 5'-rather than 3'-single-stranded tails.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.86.8.2627

Authors: S T Lovett, R D Kolodner

Institutions: Dana-Farber Cancer Institute, Harvard University

Language: English

Topic: DNA Repair Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funders: American Cancer Society, National Institutes of Health, National Institute of General Medical Sciences

Awards: G814406051, G9000150586